/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
24-10-2019  Jeff Heylmun:   Added speed of sound from compressible system
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

Global
    eigenValueCourantNo

Description
    Calculates the mean and maximum wave speed based Courant Numbers.

\*---------------------------------------------------------------------------*/

scalar CoNum = 0.0;
scalar meanCoNum = 0.0;
volScalarField speedOfSound("speedOfSound", fluid->speedOfSound());

{
    surfaceScalarField amaxSf
    (
        mag(phi) + fvc::interpolate(speedOfSound)*mesh.magSf()
    );

    scalarField sumAmaxSf
    (
        fvc::surfaceSum(amaxSf)().primitiveField()
    );


    CoNum = 0.5*gMax(sumAmaxSf/mesh.V().field())*runTime.deltaTValue();

    meanCoNum =
        0.5*(gSum(sumAmaxSf)/gSum(mesh.V().field()))*runTime.deltaTValue();
}

Info<< "Mean and max Courant Numbers = "
    << meanCoNum << " " << CoNum << endl;

// ************************************************************************* //
